Grain dryer



Aug. 23, 1966 w. A. TIMMONS, JR

GRAIN DRYER 5 Sheets-Sheet 1 Filed Sept. 18, 1963 INVENTOR WILLIAMAWMMONSJR.

Arrow/2Y5 5 Sheets-Snee't W. A. TIMMONS, JR

GRAIN DRYER INVENTOR.

ATTORNEYY Aug. 23, 1966 Filed Sept.

Aug. 23, 1966 w. A. TIMMONS, JR

GRAIN DRYER 5 Sheetsfiheet 3 Filed Sept. 18, 1963 INVENTOR WILLIAMATMMoNsJR.

A TTO/P/VEVS United States Patent 3,267,588 GRAIN DRYER William A.Timmons, Jr., 6345 Antioch Road, Merriam, Kans. Filed Sept. 18, 1963,Ser. No. 309,782 3 Claims. (Cl. 34174) This invention relates to forcedair continuous flow grain dryers, and more particularly to novelimprovements for increasing the capacity thereof.

The principal objects of the present invention are: to provide a graindryer of the above type so constructed that the drying and cooling airflow rate may be substantially increased without blowing grain from theapparatus; to provide such a device having an unusually large drying andcooling capacity in a relatively small space; to provide such graindrying apparatus which offers the benefit of frequent, eflicient grainpath splitting and substantially continuous movement along the entireflow path for producing uniform drying in the drying portion withoutoverheating; to provide such apparatus which minimizes the danger offires in the grain during drying; to provide such a device which usescurved or parabolic intake and exhaust air flow ducts which are closedbut perforated at the bottom as well as the top portions for forcingdrying and cooling air with more even distribution through the flowinggrain; to provide such an apparatus which has high air fiow rateswithout separating large quantities of dust and fine particles from thegrain; to provide such a grain dryer which is self-cleaning with noledges or obstructions to retard grain flow or to hang up trash; and toprovide such a device which is relatively simple and inexpensive inconstruction and reliable in use.

Other objects and advantages of this invention will become apparent fromthe following description taken in connection with the accompanyingdrawings wherein are set forth by way of illustration and examplecertain embodiments of this invention.

FIG. 1 is a side elevation of a grain dryer embodying this inventionwith portions broken away to show the interior thereof and air flowpaths therethrough.

FIG. 2 is an end elevation of the grain dryer with portions broken awayto show air flow paths and grain flow discharge gates.

FIG. 3 is a detailed fragmentary side elevation on an enlarged scaleshowing the covered end of an air flow duct.

FIG. 4 is a fragmentary end elevation on an enlarged scale particularlyillustrating the air flow pattern between adjacent inlet and outletducts.

FIG. 5 is a fragmentary end elevation on an enlarged scale showing theoscillating discharge gates and adjacent parts.

Referring to the drawings in more detail:

The reference numeral 1 generally indicates a portable grain dryer,however, the dryer 1 may be of the stationary variety without departingfrom the scope of this invention. The dryer 1 is of the continuous grainflow type having an elongated upwardly extending body 2 resting, in theillustrated example, on suitable wheels 2'. The body 2 includes a pairof oppositely positioned spaced apart air inlet and air outlet walls 3and 4 respectively and side walls 5 and 6 connected between the walls 3and 4. The air inlet wall 3 and outlet Wall 4 respectively have severalrows 7 of horizontally aligned vertically staggered spaced apartoutwardly flanged openings 8. A plurality of spaced apart parallelhorizontal air flow ducts generally designated 9 respectively extendbetween the inlet and outlet walls 3 and 4 and are mounted at oppositeends thereof in the flanged openings 8 by means of suitable screws andmating nuts 10 forming horizontal rows of said ducts which arevertically staggered and are easily removed for service and/ orreplacement by removing the screws and nuts 10. Blanks or caps 11 inselected positions are also engaged by the screws and nuts 10 and plugthe ends of alternate rows of the ducts 9 at the outlet wall 4 forminginlet ducts 12 open only at the inlet wall 3. Additional blanks or caps13 plug the ends of the remaining or alternate rows of ducts at theinlet wall 3 forming outlet ducts 14 open only at the outlet wall 4.

Sheet metal walls 15 are fixed to the body 2 at the inlet wall 3 andform an inlet chamber 16 communicating with the inlet ducts 12. Sheetmetal walls 17 are fixed to the body 2 at the outlet wall 4 and form anoutlet chamber 18 communicating with the outlet ducts 14. A ring or cagemember 19 is mounted on the sheet metal walls 17 and forms a circularpassageway 20 communicating with the outlet chamber 18. A fan 21, in theillustrated example of the axial flow blade type, is rotatably mountedin the ring member 19 by means of a suitable shaft 22 and supported byconventional bearings 22 having a pulley 23 fixed thereto. A belt 24 isoperatively engaged with the pulley 23 and also with a pulley 25 mountedon and driven by a motor 26 or a suitable power take-off shaft (notshown) for rotating the fan 21. The fan 21 causes air to flow outwardlythrough the passageway 20 in the direction indicated by the arrows 27which results in the exhausting of air from the outlet chamber 18. Thisdrops the pressure in the chamber 18 and induces flow through the ducts12 and 14 as noted below.

A fixed bafiie plate 28 extends outwardly and downwardly from the airinlet wall 3 and divides the inlet chamber 16 into an upper portion 29communicating with the inlet ducts 12 at the upper portion of the body 2and a lower portion 30 communicating with the inlet ducts 12 at thelower portion of the body 2.

A burner assembly 31 which may be fired by any suitable fuel is mountedin the inlet chamber 16 and normally communicates only with the chamberupper portion 29 due to the normal position of a hinged bafiie plate 32adjacent the bafiie plate 28. The baffle plate 32, however, is movableabout a hinge 33 to a position indicated by the broken lines at 34. Themovement of the battle plate 32. is by means of suitable pivoted links35 and 36, the latter being manipulated by a handle 37. When the baffleplate 32 is in the position indicated by the broken lines at 34, theburner assembly 31 communicates also with the chamber lower portion 30.A suitable hinged screen 38 provides access to the handle 37 and anopening into the inlet chamber 16 permitting air to enter throughseparate paths into the upper and lower portions 29 and 30 when thebaffle plate 32 is in the vertical position illustrated. When the battleplate is in the position at 34, all air entering the chamber 16 isforced past the burner 31 resulting in heated air entering both theupper and lower portions 29 and 30.

The exterior surfaces of the inlet and outlet ducts 12 and 14 and theinterior surfaces of the inlet and outlet walls 3 and 4 and side walls 5and 6 define a duct-interrupted grain flow chamber 39 through which thegrain flows downwardly over the respective ducts. A grain inlet hood orgarner 40 is secured on the body 2 at the upper end thereof andcommunicates with the grain flow chamber 39. A suitable grain feedingdevice such as a screw conveyor 41 communicates with the hood all forcontinuously depositing grain 42 into the flow chamber 39.

A plurality of discharge funnels 43 direct the grain 42 at the bottom ofthe how chamber 39 to oscillating grain discharge gates 44 which permitthe grain to fall therepast at a predetermined adjustable rate into adischarge hopper 45 secured to the body 2 beneath the gates 44. Asuitable conveyor device, in the illustrated example, a screw conveyor46, communicates with the discharge hopper 45 for carrying the driedgrain away from the dryer 1.

The discharge gates 44 are supported between pairs of pivotally mountedend plates 47 for rocking in an arc about respective pivot points 48.The end plates 47 are tied together by rods 49 pivotally securedrespectively thereto. A push arm 50 is pivotally secured at one endthereof to a rod 4%. The other end of the push arm 50 threadedly engagesa screw 51 at 52 for vertical adjusting movement along a slot 53 formedin a rocker arm 54. The screw 51 is manually rotatable by a knob 51'reached through an access door 52. The rocker arm 54 is pivotallysecured to the body 2 centrally of the slot 53 at 55 and a push rod 56is pivoted at one end thereof to the rocker arm 54 below the slot 53.The push rod 56 is pivotally mounted at the other end thereof to arotating link 57fixed to a shaft 58 which forms the output of a gearreducer 58'. The input shaft of the gear reducer 58 supports a pulley 59which is engaged with a belt 60 also engaging a pulley mounted on themotor 26 or power take-off shaft (not shown) whereby the discharge gates44 are operated together with the fan 21. A shear pin or similar device(not shown) is associated with the rotating link 57 for automaticallydisengaging same if a foreign object should jam the discharge gates.

The ducts 12 and 14 when viewed in cross-section respectively formclosed figures which are symmetrical about a central vertical planeextending longitudinally of the duct. The ducts are generally parabolicon each side with the vertex 61 thereof midway between the top 62 andbottom 63 thereof. This renders the top and bottom of the ducts pointedwhile the sides curve smoothly continuously outwardly and downwardly tothe vertical center or vertex and then inwardly to the bottom. Due tothis configuration, the path of the grain 42 flowing downwardly throughthe grain flow chamber 39 is split and smoothly flows around theindividual ducts as indicated by the arrows 64. The walls 65 of theducts are preferably sheet metal of approximately ZO-gauge in thicknessand perforated with -inch staggered holes 66 on -inch centers oversubstantially the entire surface thereof. This permits air flowoutwardly through the walls of the inlet ducts l2 and inwardly throughthe Walls of the outlet ducts 14.

In operation, the grain 42 is directed into the inlet hood 4t) by thescrew conveyor 41 from which it falls into the grain flow chamber 39.The flow chamber 39 is permitted to fill without oscillation of thedischarge gates 44 whereby the grain initially deposited forms astationary batch surrounding the respective ducts 12 and 14. The baflieplate 32 is then moved by means of the handle 37 to the positionindicated by the broken lines at 34 and the burner assembly 31 isactuated along with the fan '21, the discharge gates 44 remainingstationary. Heated drying air is thereby drawn through the entire grainbatch by induction which causes the heated air to enter into all theinlet ducts 12, how out of the inlet duct perforations through the grain42, enter into the perforations on adjacent outlet ducts and flow fromthe respective outlet ducts into the outlet chamber 18 where it isexhausted through the passageway 20. After several minutes of batchoperation, the battle plate 32 is moved back to its vertical positionand, after a pause, in order for the lower portion of the grain to cool,the gates 44 are actuated by rotating the screw knob 51 along withactuating the screw conveyor 46 for inducing a continuous downward flowof grain through the flow chamber 39. The air heated by the burner 31 isnow restricted to the ducts communicating with the upper portion 29 ofthe inlet chamber 16 and air entering the lower portion fit) is ofambient temperature for cooling the grain in the lower portion ofthefiow chamber 39. Cool dried grain is then continuously delivered intothe hopper 45.

A significant advantage of this invention results from the air flowpattern produced by the configuration of the inlet and outlet ducts.Because the ducts are closed to the grain except for small perforations,high flow rates may be used without blowing grain through the outletducts into the outlet chamber 18 which often occurs with the well knownopen-bottom baflle type of dryer. Most important, the curvedconfiguration coupled with the perforated duct walls produces fiowpatterns 67 which move in generally radial lines or lines normal to walltangents both into and out of the grain between adjacent inlet andoutlet ducts. This exposes a much greater percentage of grain to dryingair at any one instant than prior art duct type dryers permitting moreefiicient and homogeneous removal of moisture without the need forexcessively high temperature air which would have adverse effects on thegrain. The flow patterns 67 are produced without forming a grain deadspot at the top 62 of the ducts which would occur if the ducts wereround in crosssection instead of pointed at upper and lower ends. Thisduct cross-sectional configuration also offers less grain resistance todownward grain flow while efficiently inducing grain fiow splitting forbetter grain exposure without causing a drop-away or unfilled areaimmediately beneath the respective bottom portions 63.

Due to the more uniform distribution of drying air throughout the grain,the maximum air velocity may be maintained without sacrificingetficiency at a low enough rate so that excessive dust is not dislodgedwhich would cause an unwanted weight loss in the grain, poor workingconditions around the apparatus and sometimes the possibility of fire inthe grain. The staggered positioning of the ducts, along with the uniquecross-sectional shape and perforations, also produces a continuousturning of the grain which further increases uniform grain drying andhigher quality in the dried grain. It is estimated that the air fiow inthe above-described grain dryer may be increased approximately threetimes over the usual open-bottom baflie type grain dryer resulting in anincrease of the drying and cooling capacity by approximately 300percent.

It is to be understood that while one form of this invention has beenillustrated and described, it is not to be limited to the specific formor arrangement of parts herein described and shown except insofar assuch limitations are included in the claims.

What I claim and desire to secure by Letters Patent is:

1. In a grain dryer, a grain-containing chamber having a plurality ofgenerally horizontally extending inlet and outlet air ducts extendingtherethrough, said ducts each being closed in cross-section with the topand bottom thereof pointed vertically and the side curving smoothlycontinuously outwardly and downwardly from said top and then inwardly tosaid bottom, said ducts having walls. perforated with spaced apartair-transmitting holes, said holes being of a size unable to pass graintherethrough.

2. The apparatus as set forth in claim 1 wherein said ducts aregenerally parabolic on each side with the vertex thereof midway betweensaid top and bottom.

ducts are vertically pointed and the sides thereof curve smoothlycontinuously outwardly t0 the vertical center thereof and then inwardlyto said bottom, said ducts being adapted for splitting the downward flowof grain thereover, said ducts having walls of sheet metal perforatedwith staggered holes over substantially the entire surface thereof, saidholes being of insufiicient size to admit grain.

References Cited by the Examiner UNITED STATES PATENTS 260,567 7/1882Hawkenson 34174 336,905 3/1886 Ehlermann et al. 34--174 1,239,216 9/1917Randolph 34174 FOREIGN PATENTS 459,127 10/1913 France.

10 FREDERICK L. MATTESON, JR., Primary Examiner.

NORMAN YUDKOFF, Examiner.

F. E. DRUMMOND, Assistant Examiner.

1. IN A GRAIN DRYER, A GRAIN-CONTAINING CHAMBER HAVING A PLURALITY OFGENERALLY HORIZONTALLY EXTENDING INLET AND OUTLET AIR DUCTS EXTENDINGTHERETHROUGH, SAID DUCTS EACH BEING CLOSED IN CROSS-SECTION WITH THE TOPAND BOTTOM THEREOF POINTED VERTICALLY AND THE SIDE CURVING SMOOTHLYCONTINUOUSLY OUTWARDLY AND DOWNWARDLY FROM SAID TOP AND THEN INWARDLY TOSAID BOTTOM, SAID DUCTS HAVING WALLS PERFORATED WITH SPACED APARTAIR-TRANSMITTING HOLES, SAID HOLES BEING OF A SIZE UNABLE TO PASS GRAINTHERETHROUGH.